Exercise 2. Observe
that the subroutine NewtonSystem involves vector functions and
is not dependent on the dimension.
Use the subroutine NewtonSystem to solve the nonlinear system in 3D
space:
Hint. There are four
solutions. Good starting vectors are
.
Solution 2.
First, enter the coordinate functions
and construct the vector function
using
Mathematica, and then find the Jacobian matrix
.
Second, graph the surfaces
,
and
using
Mathematica. The points of intersection are the
solutions we seek.
![[Graphics:../Images/BroydenMethodMod_gr_54.gif]](../Images/BroydenMethodMod_gr_54.gif)
(i) Use the
Newton-Raphson method to find a numerical approximation to the
solution near
.
(ii) Use the
Newton-Raphson method to find a numerical approximation to the
solution near
.
(iii) Use the
Newton-Raphson method to find a numerical approximation to the
solution near
.
(iv) Use the
Newton-Raphson method to find a numerical approximation to the
solution near
.
We are done.
Aside. We can have
Mathematica solve the system analytically. There is
a surprise.
![[Graphics:../Images/BroydenMethodMod_gr_69.gif]](../Images/BroydenMethodMod_gr_69.gif)
![[Graphics:../Images/BroydenMethodMod_gr_70.gif]](../Images/BroydenMethodMod_gr_70.gif)
Since Mathematica performs its solution using complex
number arithmetic, the first four solutions are extraneous.
The solutions that we seek are the latter four solutions where x, y,
and z are real numbers.
(c) John H. Mathews 2005